Digital signal recording devices, digital signal recording/ playback devices, and digital signal receiving/recording/playback devices

ABSTRACT

In a recording device, a recording and playback device and a receiving, recording and playback device in a system for receiving, recording and playing back a digital signal, a digital signal recording and playing back device having the function of converting an analog television signal to a digital television signal, and recording and reproducing the digital signal includes A/D converters for an analog video signal and an analog audio signal, encoders for compressing the analog video and audio signals, encoders for compressing the video and audio signals, a multiplexer for multiplexing the compressed video and audio signals, and a selector for selecting one of a received digital signal and the compressed multiplexed signal.

BACKGROUND OF THE INVENTION

The present invention relates to digital signal recording devices,digital signal recording/playback devices, and digital signalreceiving/recording/playback devices, for receiving/recording/playingback a digital signal.

JP-A-8-98164 discloses a receiving system and a recording/playing backdevice for receiving/recording a transmitted multiplexed digital signalas a conventional technique for recording/playing back a digital signal.This prior art publication describes a receiving system which includesreceiving means for receiving a transmitted multiplexed digitalinformation signal and for selecting desired information, and recordingmeans for recording the information received by the receiving means.

This prior art system is capable of recording/playing back an incomingdigital signal as it is, but it cannot convert an analog televisionsignal like terrestrial broadcasting waves used at present to a digitalsignal, and record/play back the digital signal.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a digitalsignal receiving device, a digital signal recording/playing back deviceand a digital signal receiving/recording/playing back device, having thefunctions of converting an analog television signal to a digital signal,and recording/playing back the digital signal in a digital signalreceiving/recording/playing back system.

According to one aspect of the present invention, there is provided adigital signal recording device comprising:

a digital input means for inputting to the recording device a digitalsignal indicative of video, audio, data and so forth multiplexed in apredetermined packet form;

an analog video signal input means for inputting an analog video signalto the recording device;

an analog audio signal input means for inputting an analog audio signalto the recording device;

a video A/D converter for converting the analog video signal inputted bythe analog video signal input means to a digital signal;

a video encoder for information-compressing the digital video signal towhich the analog video signal is converted by the video A/D converter;

an audio A/D converter for converting the analog audio signal inputtedby the analog audio input means to an digital signal;

an audio encoder for information-compressing the digital audio signal towhich the analog audio signal is converted by the audio A/D converter;

a multiplexing means for multiplexing at least the video signalcompressed by the video encoder and the audio signal compressed by theaudio encoder into a multiplexed signal of a predetermined packet form;and

a record selecting means for selecting one of the digital signalinputted by the digital input means and the multiplexed digital signalprovided by the multiplexing means; and

a recording means for recording the digital signal selected by therecord selecting means

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a first embodiment of the presentinvention;

FIG. 2 illustrates a packet composition and a packet multiplexingsystem.

FIGS. 3A and 3B each show a block format in the recording device;

FIG. 4 shows a track format in the recording device;

FIGS. 5A-5E each are a timing chart indicative of a packet multiplexedoutput in a multiplexer;

FIG. 6 is a block diagram of a second embodiment of the presentinvention;

FIGS. 7A-7D each are a timing chart indicative of a packet multiplexedoutput in a multiplexer of the second embodiment;

FIG. 8 is a block diagram of an arrangement which uses a bus fortransmission of signals.

FIG. 9 is a block diagram of a third embodiment of the presentinvention; and

FIG. 10 is a block diagram of a fourth embodiment of the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be described next withreference to the accompanying drawings.

FIG. 1 is a block diagram of a receiving/recording/playing back devicefor a digital broadcasting signal in a first embodiment of the presentinvention. In FIG. 1, reference numeral 1 denotes a digital broadcastingreceiving device (Integrated Receiver & Decoder: IRD), 2 arecording/playback device, 3 an encoder, 4 a digital broadcasting signalinput terminal, 5 a tuner, 6 a QPSK demodulator, 7 a forward errorcorrection (FEC) unit for correcting an error involved in thetransmission of a signal, 8 a playback changeover switch, 9 ademultiplexer, 10 a MPEG decoder, 11 an NTSC encoder, 12 an interfacebetween the devices 1 and 2, 13 a clock recovery unit, 14 a D/Aconverter, 15 a video output terminal, 16 an audio output terminal, 17 arecorded signal changeover switch, 18 a packet control circuit, 19 arecording/playback data processing, 20 a record amplifier, 21 a playbackamplifier, 22 a magnetic tape, 23 a rotary head, 24 a clock generator,25 a clock changeover switch, 26 a video input terminal, 27 an audioinput terminal, 28 a video A/D converter, 29 an audio A/D converter, 30a video encoder, 31 an audio encoder, 32 a multiplexer, and 47 a digitalsignal processor.

FIG. 2 shows a composition of a transmitted digital broadcasting signal.As shown in a packet composition of FIG. 2(A), the transmission signalhas a packet composition of 204 bytes; a 4-byte header 50; a 184-bytedata 51 representing information on a video, audio, added data, etc.,compressed in a compression system called, for example, MPEG 2 (MovingPicture Expert Group 2) as an international standard, and a 16-byteparity 52. The packets of those video, audio, added data, etc., arereceived in a multiplexing manner on a time divisional basis on atransmission line, as shown in FIG. 2(B). Generally, not only oneprogram, but also a plurality of programs of video, audio and added datais multiplexed on a time divisional basis. The header composition ofFIG. 2(C) shows a content of the header 50. In FIG. 2(C), referencenumeral 53 denotes a sync byte indicative of the head of the packet, 54a transport error indicator, 55 a payload unit start indicator, 56 atransport priority, 57 a PID indicative of attributes of the packet, 58a transport scrambling control, 59 an adaptation field control, and 60continuity counter, each showing attributes and status of the packet,composed of 4 bytes in all. The numerals appearing on top of the packeteach represent the number of bits of a respective subpacket.

A digital broadcasting signal sent from a satellite is received at thedigital broadcasting signal input terminal 4, and inputted to the tuner5 which selects and outputs a desired signal. The output from the tuner5 is demodulated by the QPSK demodulator 6 and then inputted to the FEC7, which corrects an error involved in the received digital signal inthe transmission. The output from the FEC 7 is delivered to the playbackchangeover switch 8 and the interface 12.

When the broadcasting signal is outputted from the present device, theplayback changeover switch 8 is set at a contact to input the outputfrom the FEC 7 to demultiplexer 9, which determines a type of arespective packet, using the PID 57, etc., of the header 50, separatesonly packets of a video, audio, etc., relating to a specified program,and then outputs these packets to the MPEG decoder 10. The multiplexedsignal contains a packet called, for example, a PCR (Program ClockReference) indicative of time information representing the time whencompression took place in a broadcasting station concerned. Thus, theclock recovery unit 13 reproduces a data clock 45 using this PCR. Thedecoder clock 45 reproduced by the clock recovery unit 13 is controlledso as to have the same frequency as a clock used in a compressor (notshown) which compresses video and audio data information in accordancewith the MPEG 2 in the broadcasting station. The MPEG decoder 10 expandsthe respective video and audio signals compressed in accordance with theMPEG 2, etc., by using the received separating signal and the data clock45 reproduced by the clock reproducing unit 13, and provides decodedvideo/audio signals. The video signal is converted by the NTSC encoder11 to a television analog video signal, which is then output from thevideo output terminal 15. The audio signal is converted by the D/Aconverter 14 to an analog audio signal, which is then outputted from theaudio output terminal 16.

When the received signal is recorded in the recording/playback device 2,the output from the FEC 7 is inputted to the interface 12, whichseparates packets of video and audio information and added informationrelating to a program to be recorded as in the demultiplexer 9. When thereceived signal is recorded and played back by the recording/playbackdevice 2, it is required to also record and play back programinformation required for automatic selection of a broadcasting station.Thus, in addition to the packets selected by the demultiplexer 9, theinterface 12 also selects a packet of program information relating tothe program to be recorded and converts a part of the packet of programinformation. The signal separated by the interface 12 is inputted to thepacket control circuit 18 by selecting a contact c by the recordingsignal changeover switch 17. As shown in the main data of FIG. 3A, thepacket control circuit 18 divides 188-byte packet data into 92-bytepacket data A 99 and 96-byte packet data B 100, and adds 4-byte packetheader 98 to the packet data A 99. The packet control circuit 18 alsoproduces in the packet header 98 a time stamp, shown in a hatched area102, which is data on a time when the packet is received.

As shown in FIG. 3A, additional information AUX 97 and a header 96 arefurther added by the recording/playback circuit 19 to each of the packetdata A and B, in which the packet data A already has the added header98, to thereby provide data blocks 90 and 91. The recording/playbackcircuit 19 further adds an error correction signal CIP 101, a syncsignal 92 indicative of the head of the block, signals ID1 (93) and ID2(94) representing information on the positions of the blocks, and asignal IDP 95 which represents an error check parity for the ID1 (93)and ID2 (94) are added to each of the blocks 90 and 91, and theresulting signals are recorded via the record amplifier 20 by the rotaryhead 23 onto the magnetic tape 22. FIG. 4 shows a recording format onthe magnetic tape 22 formed when the rotary head 23 rotates through 180degrees. Areas 70-76 are for a preamble, a subcode of additionalinformation, a gap, main data having the block structure of FIG. 3A, apostamble, main data, and a parity C2P for error correction in main data75, respectively. The subcode 71 has a pack composition called packdata, as shown in FIG. 3B.

In reproduction, a signal 153 reproduced by the rotary head 23 isinputted via the playback amplifier 21 to the recording/playback dataprocessing circuit 19, which detects the sync signal 92, signals ID1(93), ID2 (94), etc., and corrects errors, using the CIP 101, C2P 76,etc., extracts packet data A 99 and packet data B 100, and then sendsthose data to the packet control circuit 18. The packet control circuit18 outputs the respective packets at the same intervals of time as inthe recording in accordance with the time stamp 102 added when the datawas recorded, and then sends those packets via the interface 12 to theplayback changeover switch 8. When a reproduced picture is to beobtained, the playback changeover switch 8 is set at the contact b tothereby send a reproduced packet to the demultiplexer 9. Thedemultiplexer 9 automatically selects a broadcasting station on thebasis of the packet of program information which was selected andconverted by the interface 12 when the data was recorded, and outputsonly a packet required for the MPEG decoder 10. Video/audio signals areobtained in a manner similar to that in which an output is obtained froma broadcasting signal.

Also, in playback, the data clock 45 used in the MPEG decoder 10 isrequired to obtain the same frequency as it was compressed in thebroadcasting station. To this end, at least the respective PCR timeintervals inputted when recorded are required to be maintained,reproduced and outputted correctly. To this end, in recording, the timestamp 102 is added in the packet control circuit 18. In playback, therespective packets are outputted by the packet control circuit 18 inaccordance with the time stamps 102 to maintain the time intervals atwhich the packets are outputted. To this end, clocks used for producingthe time stamp 102 in the recording should be decoder clock 45reproduced by the clock recovery unit 13. In recording, the clockchangeover switch 25 is set at a contact e so that the decoder clock 45is inputted to the packet control circuit 18.

In reproduction, the clock recovery unit 13 of the digital broadcastingreceiver 1 is operated by a timing signal outputted from the packetcontrol circuit 18 to produce decoder clock 45. Thus, the packet controlcircuit 18 cannot use the decoder clock 45. In order to avoid-this, theclock generator 24 which generates a fixed clock 46 is provided so thatwhen the clock changeover switch 25 is set at a contact f, the fixedclock 46 is inputted to the packet control circuit 18 and a packet isoutputted at a timing generated by the fixed clock 46. Thus, the clockrecovery unit 13 is able to generate a stabilized clock depending on thefixed clock 46. The clock generator 24 generally uses a crystaloscillator. In this case, the frequency of the crystal oscillator shouldbe within the standards of MPEG 2, etc.

Recording/playback of an analog broadcasting such as a terrestrialbroadcasting performed at present in the present recording/playbackdevice will be described next.

When the analog broadcasting signal is recorded, an analog video signal150 is inputted to the video input terminal 26 of the encoder 3 of FIG.1. The video A/D converter 28 converts the analog video signal to adigital video signal. The video encoder 30 compresses the image, usingthe MPEG 2, etc., as in the compression of the digital broadcastingsignal, and outputs the compressed signal to the multiplexer 32. Ananalog audio signal 151 is inputted to the audio input terminal 27, andconverted by the audio A/D converter 29 to a digital audio signal. Theaudio encoder 31 compresses the digital audio signal, and also outputsthis signal to the multiplexer 32, which multiplexes a video stream 42produced by the video encoder 30 and an audio stream 43 produced by theaudio encoder 31.

FIGS. 5A-5E show an example of timing in the multiplexing operation. InFIGS. 5A-5E, VIs 1 (100) and 2 (111), etc., in the video stream 42represent the respective video packets compressed by the video encoder30. AUs 1 (113), 2 (114), etc., in the audio stream 43 represent therespective audio packets compressed by the audio encoder 31. Referencenumeral 44 denotes a multiplexed stream obtained from the multiplexer 32in which the length of each packet depends on a transfer rate which inturn depends on the compression rate. Generally, the transmission rateof the audio stream 43 is lower than that of the audio stream 42.

As shown in FIGS. 5A-5E, the multiplexer 32 temporarily stores the videoand audio streams 42 and 43, and outputs them as the video and audiopacket streams 45 and 46 at the same transfer rate. The multiplexer 32further outputs both the packets 45 and 46 in a time divisional manneronto a signal at a fixed transfer rate, which is generally higher thanthe sum of the transmission rates of the video and audio streams 42 and43. It further produces a packet PAT 118, PMT 119, PCR 120, SI table121, etc., on program information stipulated under the MPEG2 standards,and outputs then those data during a time when no video/audio aretransmitted. A reference symbol PMT represents the PID of packets ofvideo/audio which compose one program. A reference symbol PAT describesthe PID of a packet of a PMT corresponding to each program. A referencesymbol SI represents information on a copy guard, a code indicative ofeach of discrete points in the recording, etc. The PAT and PMT used whena signal obtained by analog-to-digital conversion and compression of ananalog broadcasting signal is recorded and reproduced may be stipulateduniquely as in the present invention or allocated to any one of theexisting programs under the digital broadcasting.

Reference symbols NULs 115, 125 and 126 denote senseless dummy datawhose quantities are each dependent on the difference between the totalnumber of packets and the transmission rate of the multiplexed stream.

As shown in FIGS. 5A-5E, the video stream 42, auido stream 43, otherpackets, and NULs are multiplexed on a time-divisional basis to form asingle signal. The respective video packets VIs 1 (110), 2 (111), etc.,on the video stream 42 are the same in content as the VIs 1 (116), 2(112) etc., on the multiplexed stream 44. Similarly, the respectiveaudio packets AUs 1 (113), 2 (114) etc., of the audio stream 43 are thesame in content as the AUs 1 (122), 2 (124) etc., of the multiplexedstream 44.

Thus, the multiplexed stream 44 has a stream composition similar to theoutput of the interface 12 of the digital broadcasting receiver 1. Thus,the recording signal changeover switch 17 selects a contact d and inputsthe multiplexed stream 44 to the packet control circuit 18 to therebyrecord/playback the multiplexed stream 44 in the same manner as thedigital broadcasting signal.

When the multiplexed stream 44 is recorded, the clock frequency used forproducing the time stamp 102 in the packet control circuit 18 isrequired to have the same frequency as the clock used in the video andaudio encoders 30 and 31, as described with respect to the recording ofthe digital broadcasting. Thus, as shown in FIG. 1, the video encoder30, audio encoder 31, and multiplexer 32 are operated at the fixed clock46 generated by the clock generator 24, the clock changeover switch 25is set at a contact f so that the fixed clock 46 is inputted to thepacket control circuit 18. Also, in playback, the clock changeoverswitch 25 is set at the contact f while the packet control circuit 18uses the fixed clock 46.

When there is a margin in the transfer rate given to therecording/playback device, the digital and analog broadcasting signalsare recordable simultaneously. FIG. 6 is a block diagram of a device forreceiving, recording and playing back a digital broadcasting signal inthis case, wherein reference numeral 2 a denotes a recording/playbackdevice. This device is different in operation from the FIG. 1 device inthat the broadcasting stream which is the output from the interface 12is also inputted to the multiplexer 32, and that the video encoder 30,audio encoder 31 and multiplexer 32 are operated with the clockoutputted from the clock changeover switch 25.

In recording, as shown in FIGS. 7A-7D, the respective broadcasting (BR),video (VI), and audio (AU) packets of the broadcasting stream 41, videostream 42, and audio stream 43 are multiplexed on a time divisionalbasis and PMT and PCR are added to the multiplexed packets to constitutea multiplexed stream. In this case, the PAT is already contained in thebroadcasting stream 41 (shown by a packet 130 of FIG. 7A), but onlycontains information on a program contained in the broadcasting stream.Thus, the information should be converted so as to include informationon the analog broadcasting. In FIG. 7D, reference numeral 131 denotes aPAT converted by the multiplexer 32.

In this case, the packet control circuit 18 uses the data clock 45produced by the clock recovery unit 13. Thus, the clock changeoverswitch is set at a contact e, and the video and audio encoders 30 and 31also use the decoder clock 45. In playback, the clock changeover switch25 is set at a contact f to use the fixed clock 46.

In playback, the user selects one of the digital and analog broadcasts,the demultiplexer 9 selects only one of the digital and analogbroadcasts on the basis of the PAT converted in the recording, andinputs the selected program packet to the MPEG decoder 10 to obtain thevideo and audio of the desired program.

Thus, the digital broadcasting signal and the digital signal to whichthe analog broadcasting signal is converted are easily recordedsimultaneously in a multichannel. If the video and audio streams 42 and43 alone are multiplexed in a mode in which no broadcasting stream 41 isoutputted in the multiplexer 32 of the FIG. 6 device, an operationalmode similar to that described in FIG. 1 is obtained. In this case, theclock changeover switch 25 is required to be set at the contact f in therecording operation. Alternatively, the video and audio signals may beselected from separate sources. For example, only the video signal maybe selected from the broadcasting stream 41 and the audio signal may beselected from the audio stream 43. Conversely, only the audio signal maybe selected from the broadcasting stream 41 and only the video signalmay be selected from the audio stream 43.

While in the above the interface 12, multiplexer 32 and packet controlcircuit 18 are described as handling a one-way signal, these elementsmay be replaced with an input/output bus. FIG. 8 shows a signal linecomposition used in this case. Reference numerals 140, 143 and 144 eachdenote a tri(3)-state buffer whose output can have a high impedance andreference numerals 141 and 142 each denote an input buffer.

In the arrangement of FIG. 8, when the digital broadcasting signal isrecorded, the buffers 143 and 144 are each set at high impedance suchthat the digital broadcasting signal is inputted from the buffer 140 viathe input buffer 142 to the packet control circuit 18. When the analogbroadcasting signal is recorded, the buffers 140 and 143 are set at highimpedance so that the analog broadcasting signal is inputted from thebuffer 144 via the input buffer 142 to the packet control circuit 18. Inplayback, the buffers 140 and 144 are set at high impedance so that thesignal of interest is inputted from the buffer 143 via the input buffer141 to the interface 12. This serves to reduce the number of signallines between the interface 12 and the packet control circuit 18.

The video A/D converter 28, audio A/D converter 29, video encoder 30,audio encoder 31 and multiplexer 32 may be built either in therecording/playback device 2 or in the digital broadcasting receiver 1.Although not shown, the demultiplexer 9, MPEG decoder 10, NTSC encoder11, and D/A converter 14 may also be provided in the recording/playbackdevice 2 as well. Thus, even the recording/playback device is capable ofproviding a reproduced video signal by itself. Of course, the digitalbroadcasting receiver 1, recording/playback device 2 and encoder 3 maybe all integrated in one unit.

While in the above description the recording/playback of a digitalsignal alone has been described, the present device may have thefunction of recording/reproducing an analog signal as in a VHS and a VTRavailable at present.

FIG. 9 is a block diagram of a receiving/recording/playback device whichis capable of selecting, recording and reproducing one of the digitaland analog signals. Like elements in FIGS. 1, 6 and 9 are identified bylike reference numerals.

In FIG. 9, reference numeral 2 b denotes a recording/playback device,reference numeral 200 denotes an analog broadcasting signal inputterminal, 201 an analog tuner, 202 an analog audio recording/playbackcircuit, 203 an analog video recording/playback circuit, 204 an analogvideo record amplifier, 205 an analog video playback amplifier, 206 asystem controller, 207 an output selector, 208 an external audio outputterminal, 209 an external video input terminal, 210 a digital recordingchangeover switch, 220 a video head, and 221 an audio head.

When a digital signal is recorded in the device of FIG. 9, the digitalrecording changeover switch 210 is set at a contact i, so that theoutput from the digital signal processor 47 is recorded via the playbackamplifier 20 onto the magnetic tape 22 by the audio head 221 of therotary head 23. Simultaneously, a servo tracking signal is recorded bythe system controller 206 in synchronism with the rotation of the rotaryhead 22. In this case, the output from the analog video record amplifier204 is stopped by the system controller 206. In playback, a video signal230 and an audio signal 231 are reproduced by the digital broadcastingreceiver 1, and selected by the output selector 270 under the control ofthe system controller 206, and outputted from the external video andaudio output terminals 209 and 208.

When the analog broadcasting signal is digitally recorded, this signalis received at the analog broadcasting signal input terminal 200, andinputted to the analog tuner 201 to produce analog video and audiosignals 150 and 151 of a desired program, which are then inputted to theencoder 3.

When the analog broadcasting signal is analog-recorded using a VHSsystem available at present, the analog broadcasting signal is similarlyreceived at the analog broadcasting signal input terminal 200, and theninputted to the analog tuner 201 to produce analog video and audiosignals 150 and 151 of the desired program. The analog video signal 150is processed by the analog video recording/playback circuit 203 so as tobe a signal, for example, conforming to VHS standards, which signal isthen recorded via the analog video record amplifier 204 by the videohead 220 of the rotary head 23. Simultaneously, the analog signal. 151is produced by the analog audio recording/playback circuit 202 so as tobe a signal, for example, conforming to the VHS standards, and thenrecorded via the digital recording changeover switch 210 set at acontact h and the record amplifier 20 by the audio head 221 of therotary head 23. A servo tracking signal is recorded as in the digitalrecording. The video and audio heads 220 and 221 are different inazimuth angle and azimuth-record the video and audio signals.

Because of an azimuth loss in reproduction, the signal recorded by thevideo head 220 is reproduced by the video head 220 alone while thesignal recorded by the audio head 221 is reproduced by the audio head221 alone. The video signal reproduced by the video head 220 isreproduced via the analog video playback amplifier 205 by the analogvideo recording/playback processing circuit 203 to produce a reproducedvideo signal 232, which is then outputted via the output selector 207from the external video terminal 209. The audio signal reproduced by theaudio head 221 is processed by the analog audio recording/playbackprocessing circuit 202 via the reproduction amplifier 21 to produce areproduced audio signal 233, which is then outputted via the outputselector 207 from the external audio terminal 208.

In this case, generally, the digital recording is different in thefeeding speed of the magnetic tape 22 from the analog recording. Thesystem controller 206 controls the mode so that for example, a standardmode (SP mode) or a triple mode (EP mode) in the VHS standards is usedin the analog recording while a double mode (LP mode) (½ of the tapefeeding speed in the standard mode, i.e., the recording time is doubled)is used in the digital recording. In view of the possibility thatdigital recording is performed only on a specified tape (for example, anS-VHS tape conforming to the VHS standards), so that the systemcontroller 206 detects the type of a tape (generally, depending on thepresence of holes in a cassette) and if the tape is different from theS-VHS tape, the system controller 206 always performs an analogrecording operation.

In this case, the digital broadcasting signal cannot be digitallyrecorded as it is so that as shown in FIG. 10, the video and audiosignals 230 and 231 produced by the broadcasting signal receiver 1 areinputted via an input selector 250 to the analog video and audiorecording/playback processing circuits 203 and 202 to perform analogrecording operation.

In playing back, the system controller 206 detects a servo trackingsignal to determine the tape speed in the recording operation andautomatically selects analog playback in the standard and triple modesand digital playback in the double mode. Thus, the user is not requiredto pay attention to whether the broadcasting signal is digital-recordedor analog-recorded. The mode is automatically changed to a predeterminedmode to thereby provide desired signals from the external video andaudio output terminals 209 and 208.

The digital broadcasting receiver 1 may be another device without theoutput selector 207 so that the output from the digital broadcastingsignal receiver 1 may be independent of the outputs from the analogvideo and audio playback processing circuits 203 and 202.

While in the above the magnetic tape is used as a recording medium, amagnetic disk, optical disk, semiconductor memory or other recordingmedium may be used. Although not shown in FIGS. 1 and 6, a decipheringcircuit which deciphers a cipher signal may be provided between the QPSKdemodulator 6 and the FEC 7. Selection of a packet and conversion of apacket on the program information by the interface 12 may be performedby the demultiplexer 9 or packet control circuit 18.

In the recording device, recording/playback device, andreceiving/recording/playback device, for a digital broadcasting signal,according to the present invention, the analog television signal isconverted to a digital signal, which is then recorded and reproduced.The digital broadcasting signal and the digital signal to which theanalog television signal is converted are recorded simultaneously in amultichannel.

What is claimed is:
 1. A digital signal recording device comprising: adigital signal input unit which inputs to the digital signal recordingdevice a digital signal indicative of video and audio multiplexed in apredetermined packet format; an analog video signal input unit whichinputs an analog video signal to the digital signal recording device; ananalog audio signal input unit which inputs an analog audio signal tothe digital signal recording device; a video A/D converter whichconverts the analog video signal inputted by the analog video signalinput unit to a digital video signal; a video encoder which compressesthe digital video signal to which the analog video signal is convertedby the video A/D converter; an audio A/D converter which converts theanalog audio signal inputted by the analog audio signal input unit to adigital audio signal; an audio encoder which compresses the digitalaudio signal to which the analog audio signal is converted by the audioA/D converter; a multiplexer which multiplexes at least the digitalvideo signal compressed by the video encoder, the digital audio signalcompressed by the audio encoder, a code indicative of time information,and a code indicative of program information into a multiplexed digitalsignal having the predetermined packet format; a recording selectingunit which outputs a selected one of the digital signal inputted by thedigital signal input unit and the multiplexed digital signal produced bythe multiplexer as a digital recording signal; an external clock inputunit which inputs an external clock to the digital signal recordingdevice; a clock generator which generates an internal clock for use inat least one of the video encoder and the audio encoder; a clockselecting unit which outputs a selected one of the external clockinputted by the external clock input unit and the internal clockgenerated by the clock generator as a selected clock; an input timeadding unit which generates information about respective output times ofpackets of the digital recording signal outputted by the recordingselecting unit, using the selected clock outputted by the clockselecting unit, and adds the information about the respective outputtimes to the digital recording signal; and a recording unit whichrecords the digital recording signal outputted by the recordingselecting unit; wherein the digital signal recording device is operablein a first recording mode in which the digital signal inputted by thedigital signal input unit is outputted by the recording selecting unitas the digital recording signal and recorded by the recording unit, anda second recording mode in which the multiplexed digital signal producedby the multiplexer is outputted by the recording selecting unit as thedigital recording signal and recorded by the recording unit; and whereinthe clock selecting unit outputs the external clock as the selectedclock in the first recording mode, and outputs the internal clock as theselected clock in the second recording mode.
 2. A digital signalrecording and reproducing device comprising: a digital signal input unitwhich inputs to the digital signal recording and reproducing device adigital signal indicative of video and audio multiplexed in apredetermined packet format; an analog video signal input unit whichinputs an analog video signal to the digital signal recording andreproducing device; an analog audio signal input unit which inputs ananalog audio signal to the digital signal recording and reproducingdevice; a video A/D converter which converts the analog video signalinputted by the analog video signal input unit to a digital videosignal; a video encoder which compresses the digital video signal towhich the analog video signal is converted by the video A/D converter;an audio A/D converter which converts the analog audio signal inputtedby the analog audio signal input unit to a digital audio signal; anaudio encoder which compresses the digital audio signal to which theanalog audio signal is converted by the audio A/D converter; amultiplexer which multiplexes at least the digital video signalcompressed by the video encoder, the digital audio signal compressed bythe audio encoder, a code indicative of time information, and a codeindicative of program information into a multiplexed digital signalhaving the predetermined packet format; a recording selecting unit whichoutputs a selected one of the digital signal inputted by the digitalsignal input unit and the multiplexed digital signal produced by themultiplexer as a digital recording signal; an external clock input unitwhich inputs an external clock to the digital signal recording andreproducing device; a clock generator which generates an internal clockfor use in at least one of the video encoder and the audio encoder; aclock selecting unit which outputs a selected one of the external clockinputted by the external clock input unit and the internal clockgenerated by the clock generator as a selected clock; an input timeadding unit which generates information about respective output times ofpackets of the digital recording signal outputted by the recordingselecting unit, using the selected clock outputted by the clockselecting unit, and adds the information about the respective outputtimes to the digital recording signal; and a recording and reproducingunit which records the digital recording signal outputted by therecording selecting unit in a recording mode, and reproduces therecorded digital signal in a reproducing mode; wherein the digitalsignal recording and reproducing device is operable in a first recordingmode in which the digital signal inputted by the digital signal inputunit is outputted by the recording selecting unit as the digitalrecording signal and recorded by the recording and reproducing unit, anda second recording mode in which the multiplexed digital signal producedby the multiplexer is outputted by the recording selecting unit as thedigital recording signal and recorded by the recording and reproducingunit; and wherein the clock selecting unit outputs the external clock asthe selected clock in the first recording mode, and outputs the internalclock as the selected clock in the second recording mode and thereproducing mode.
 3. A digital signal receiving, recording, andreproducing device comprising: a digital signal receiving device whichreceives a digital signal, outputs a digital signal, and receives areproduced digital signal; and a digital signal recording andreproducing device which receives the digital signal outputted by thedigital signal receiving device, records the received digital signal,reproduces the recorded digital signal, and outputs the reproduceddigital signal to the digital signal receiving device; wherein thedigital signal receiving device comprises: a digital signal input unitwhich inputs to the digital signal receiving device a digital signalincluding at least one modulated digital channel signal, each of the atleast one modulated digital channel signal including at least onedigital signal indicative of video and audio multiplexed in apredetermined packet format; an input processing unit which demodulatesa modulated digital channel signal from the digital signal inputted bythe digital signal input unit, and outputs the demodulated digitalchannel signal, the demodulated digital channel signal including atleast one digital signal indicative of video and audio multiplexed inthe predetermined packet format; a reproducing selecting unit whichoutputs a selected one of the demodulated digital channel signaloutputted by the input processing unit and the reproduced digital signaloutputted by the digital signal recording and reproducing device as anoutput digital signal; a separating unit which separates a selecteddigital signal indicative of video and audio multiplexed in thepredetermined packet format from the output digital signal outputted bythe reproducing selecting unit, and outputs the separated digitalsignal; a clock reproducing unit which reproduces a first clock from theseparated digital signal outputted by the separating unit; and a decoderwhich decodes the separated digital signal outputted by the separatingunit into a television signal using the first clock; wherein the digitalsignal recording and reproducing device comprises: an analog videosignal input unit which inputs an analog video signal to the digitalsignal recording and reproducing device; an analog audio signal inputunit which inputs an analog audio signal to the digital signal recordingand reproducing device; a video A/D converter which converts the analogvideo signal inputted by the analog video signal input unit to a digitalvideo signal; a video encoder which compresses the digital video signalto which the analog video signal is converted by the video A/Dconverter; an audio A/D converter which converts the analog audio signalinputted by the analog audio signal input unit to a digital audiosignal; an audio encoder which compresses the digital audio signal towhich the analog audio signal is converted by the audio A/D converter; amultiplexer which multiplexes at least the digital video signalcompressed by the video encoder, the digital audio signal compressed bythe audio encoder, a code indicative of time information, and a codeindicative of program information into a multiplexed digital signalhaving the predetermined packet format; a recording selecting unit whichoutputs a selected one of the demodulated digital signal outputted bythe input processing unit of the digital signal receiving device and themultiplexed digital signal produced by the multiplexer as a digitalrecording signal; a clock generator which generates a second clock foruse in at least one of the video encoder and the audio encoder; a clockselecting unit which outputs a selected one of the first clock and thesecond clock as a selected clock; an input time adding unit whichgenerates information about respective output times of packets of thedigital recording signal outputted by the recording selecting unit,using the selected clock outputted by the clock selecting unit, and addsthe information about the respective output times to the digitalrecording signal; and a recording and reproducing unit which records thedigital recording signal outputted by the recording selecting unit in arecording mode, and reproduces the recorded digital signal and outputsthe reproduced digital signal to the reproducing selecting unit of thedigital signal receiving device in a reproducing mode; wherein thedigital signal recording and reproducing device is operable in a firstrecording mode in which the demodulated digital signal outputted by theinput processing unit of the digital signal receiving device isoutputted by the recording selecting unit as the digital recordingsignal and recorded by the recording and reproducing unit, and a secondrecording mode in which the multiplexed digital signal produced by themultiplexer is outputted by the recording selecting unit as the digitalrecording signal and recorded by the recording and reproducing unit; andwherein the clock selecting unit outputs the first clock as the selectedclock in the first recording mode, and outputs the second clock as theselected clock in the second recording mode and the reproducing mode.